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Abstract:

The present invention provides a liquid crystal display (LCD) apparatus.
The LCD apparatus comprises a TFT-LCD module and a corresponding phase
retarder, and a light adjustment plate is disposed between the TFT-LCD
module and the phase retarder and configured to reduce an optical path
difference of a light emitted from the phase retarder. Alternatively, the
TFT-LCD module comprises a light adjustment plate configured to reduce
the optical path difference of the light emitted from the phase retarder.
The present invention can mitigate crosstalk when viewing 3D images.

Claims:

1. A liquid crystal display (LCD) apparatus comprising a thin film
transistor (TFT)-LCD module and a corresponding phase retarder,
characterized in that: a light adjustment plate is disposed between the
TFT-LCD module and the phase retarder and configured to reduce an optical
path difference of a light emitted from the phase retarder, and a
refractive index of the light adjustment plate is larger than a
refractive index of a liquid crystal layer of the TFT-LCD module, and a
thickness and the refractive index of the light adjustment plate are
varied for reducing the optical path difference of the light emitted from
the phase retarder, and the refractive index of the light adjustment
plate is in the range of 1.5 to 1.7, and the light adjustment plate
includes a black matrix for reducing crosstalk, and the phase retarder
comprises an assembly of a zero-wave phase plate and a half-wave
(λ/2) phase retarder, or an assembly of quarter-wave (λ/4)
phase retarder having slow-axis angles of 45 degrees and 135 degrees.

2. An LCD apparatus comprising a TFT-LCD module and a corresponding phase
retarder, characterized in that: a light adjustment plate is disposed
between the TFT-LCD module and the phase retarder and configured to
reduce an optical path difference of a light emitted from the phase
retarder.

3. The LCD apparatus according to claim 2, characterized in that: a
refractive index of the light adjustment plate is larger than a
refractive index of a liquid crystal layer of the TFT-LCD module.

4. The LCD apparatus according to claim 3, characterized in that: the
optical path difference of the light emitted from the phase retarder is
reduced by increasing a thickness of the light adjustment plate.

5. The LCD apparatus according to claim 3, characterized in that: the
optical path difference of the light emitted from the phase retarder is
reduced by increasing a refractive index of the light adjustment plate.

6. The LCD apparatus according to claim 3, characterized in that: a
thickness and a refractive index of the light adjustment plate are varied
for reducing the optical path difference of the light emitted from the
phase retarder.

7. The LCD apparatus according to claim 4, characterized in that: the
refractive index of the light adjustment plate is in the range of 1.5 to
1.7.

8. The LCD apparatus according to claim 5, characterized in that: the
refractive index of the light adjustment plate is in the range of 1.5 to
1.7.

9. The LCD apparatus according to claim 6, characterized in that: the
refractive index of the light adjustment plate is in the range of 1.5 to
1.7.

10. The LCD apparatus according to claim 4, characterized in that: the
light adjustment plate includes a black matrix for reducing crosstalk.

11. The LCD apparatus according to claim 5, characterized in that: the
light adjustment plate includes a black matrix for reducing crosstalk.

12. The LCD apparatus according to claim 6, characterized in that: the
light adjustment plate includes a black matrix for reducing crosstalk.

13. The LCD apparatus according to claim 4, characterized in that: the
phase retarder comprises an assembly of a zero-wave phase plate and a
λ/2 phase retarder, or an assembly of λ/4 phase retarder
having slow-axis angles of 45 degrees and 135 degrees.

14. The LCD apparatus according to claim 5, characterized in that: the
phase retarder comprises an assembly of a zero-wave phase plate and a
λ/2 phase retarder, or an assembly of λ/4 phase retarder
having slow-axis angles of 45 degrees and 135 degrees.

15. The LCD apparatus according to claim 6, characterized in that: the
phase retarder comprises an assembly of a zero-wave phase plate and a
λ/2 phase retarder, or an assembly of λ/4 phase retarder
having slow-axis angles of 45 degrees and 135 degrees.

16. A LCD apparatus comprising a TFT-LCD module and a corresponding phase
retarder disposed on the TFT-LCD module, characterized in that: the
TFT-LCD module comprises a light adjustment plate configured to reduce an
optical path difference of a light emitted from the phase retarder.

Description:

FIELD OF THE INVENTION

[0001] The present invention relates to a field of a liquid crystal
display (LCD) technology, and more particularly to an LCD apparatus
capable of reducing crosstalk between pixels and effects on
two-dimensional (2D) images of the display.

BACKGROUND OF THE INVENTION

[0002] With the development of the three-dimensional (3D) display
technology, the requirement for using a 3D display to view 3D images is
higher and higher. Referring to FIG. 1, FIG. 1 is a cross-sectional view
of a normal 3D display cooperated with glasses and comprising a thin film
transistor (TFT)-LCD module and a phase retarder. Pixels signals of the
3D display are alternately displayed from above to below for a viewer's a
left eye and a right eye. Referring to FIG. 2, the signals of the display
are displayed in a manner of rows and received by the viewer's eyes.

[0003] The phase retarder is bonded to a front side of the TFT-LCD module.
According to the displayed pixel signals of the display, the phase
retarder can provide different phase retardation for the left and right
eyes, respectively. Therefore, the signals with the same vertical
polarization state emitted from the TFT-LCD module are transformed into
different polarized lights for the left and right eyes. Referring to FIG.
1, when the polarization state of the light emitted from the TFT-LCD
module is the vertical polarization state, the pixel signals for right
eye are transformed into horizontally polarized lights by a half-wave
(λ/2) phase retarder, and the pixel signals for left eye remain the
vertical polarization state by using a zero-wave phase plate, and the
pixel signals are then separated for the left and right eyes by using a
polarizer glasses.

[0004] However, there is a defect exiting in the design of FIG. 1. That
is, viewing angle thereof is limited to ±θ1. When the viewing
angle exceeds ±θ1, the pixel signals for left eye may pass
through the λ/2 phase retarder, and the pixel signals for right eye
may pass through the zero-wave phase plate. Therefore, the pixel signals
for right eye which pass through the zero-wave phase plate further pass
through a left polarizer glass which is used to receive the pixel signals
for left eye, and the pixel signals for left eye which pass through the
λ/2 phase retarder further pass through a right polarizer glass
which is used to receive the pixel signals for right eye, and then
crosstalk arises. That is, a traction phenomena appears on a background
of a display frame with high contrast.

[0005]FIG. 3 shows a method for improving crosstalk of the LCD which
includes a black matrix between the λ/2 phase retarder and the
zero-wave phase plate of the phase retarder. A width a of the λ/2
phase retarder and the zero-wave phase plate is reduced to a width b, so
as to widen a angle for allowing the pixel signal to pass the phase
retarder, hence increasing the viewing angle without crosstalk. However,
when using the LCD to view 2D images, the brightness of the 2D images
displayed by the LCD is reduced by the black matrix.

SUMMARY OF THE INVENTION

[0006] A primary object of the present invention is to provide an LCD
apparatus, so as to solve the problem that crosstalk easily appears when
viewing the 3D images, thereby deteriorating the display quality, and the
brightness of the 2D images is reduced.

[0007] The present invention can be achieved as below.

[0008] The present invention provides a liquid crystal display (LCD)
apparatus comprising a thin film transistor (TFT)-LCD module and a
corresponding phase retarder, wherein a light adjustment plate is
disposed between the TFT-LCD module and the phase retarder and configured
to reduce an optical path difference of a light emitted from the phase
retarder, and a refractive index of the light adjustment plate is larger
than a refractive index of a liquid crystal layer of the TFT-LCD module,
and a thickness and the refractive index of the light adjustment plate
are varied for reducing the optical path difference of the light emitted
from the phase retarder, and the refractive index of the light adjustment
plate is in the range of 1.5 to 1.7, and the light adjustment plate
includes a black matrix for reducing crosstalk, and the phase retarder
comprises an assembly of a zero-wave phase plate and a half-wave
(λ/2) phase retarder, or an assembly of quarter-wave (λ/4)
phase retarder having slow-axis angles of 45 degrees and 135 degrees.

[0009] The present invention further provides an LCD apparatus comprising
a TFT-LCD module and a corresponding phase retarder, wherein a light
adjustment plate is disposed between the TFT-LCD module and the phase
retarder and configured to reduce an optical path difference of a light
emitted from the phase retarder.

[0010] In one embodiment of the present invention, a refractive index of
the light adjustment plate is larger than a refractive index of a liquid
crystal layer of the TFT-LCD module.

[0011] In one embodiment of the present invention, the optical path
difference of the light emitted from the phase retarder is reduced by
increasing a thickness of the light adjustment plate.

[0012] In one embodiment of the present invention, the optical path
difference of the light emitted from the phase retarder is reduced by
increasing a refractive index of the light adjustment plate.

[0013] In one embodiment of the present invention, a thickness and a
refractive index of the light adjustment plate are varied for reducing
the optical path difference of the light emitted from the phase retarder.

[0014] In one embodiment of the present invention, the refractive index of
the light adjustment plate is in the range of 1.5 to 1.7.

[0015] In one embodiment of the present invention, the light adjustment
plate includes a black matrix for reducing crosstalk.

[0016] In one embodiment of the present invention, the phase retarder
comprises an assembly of a zero-wave phase plate and a λ/2 phase
retarder.

[0017] In one embodiment of the present invention, the phase retarder
comprises an assembly of λ/4 phase retarder having slow-axis angles
of 45 degrees and 135 degrees.

[0018] The conventional LCD has the problem that crosstalk easily appears
when viewing the 3D images, thereby deteriorating the display quality,
and the brightness of the 2D images is reduced. In comparison with the
conventional LCD, the LCD apparatus comprises the light adjustment plate
disposed between the TFT-LCD module and the phase retarder, and
configured to reduce the optical path difference of the light emitted
from the phase retarder, so as to reduce crosstalk when viewing the 3D
images, and to mitigate the problem that the brightness of the 2D images
is reduced.

[0019] The structure and the technical means adopted by the present
invention to achieve the above and other objects can be best understood
by referring to the following detailed description of the preferred
embodiments and the accompanying drawings.

[0022]FIG. 3 is a structural diagram showing the conventional LCD
including a black matrix on a phase retarder; and

[0023] FIG. 4 is a schematic diagram showing an LCD apparatus according to
a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The following embodiments are referring to the accompanying
drawings for exemplifying specific implementable embodiments of the
present invention. Furthermore, directional terms described by the
present invention, such as upper, lower, front, back, left, right, inner,
outer, side and etc., are only directions by referring to the
accompanying drawings, and thus the used directional terms are used to
describe and understand the present invention, but the present invention
is not limited thereto.

[0025] In the drawings, structure-like elements are labeled with like
reference numerals.

[0026] In a preferred embodiment of the present invention, FIG. 4 is
structural diagram showing an LCD apparatus according to the preferred
embodiment of the present invention. The LCD apparatus 100 comprises a
TFT-LCD module 110 and a corresponding phase retarder 120. The TFT-LCD
module 110 comprises pixels 111 for left eye signals and pixels 112 for
right eye signals. The pixels 111 for left eye signals cooperate with a
phase retarder 120 to emit polarized signals, and the pixels 112 for
right eye signals cooperate with another phase retarder 120 to emit
polarized signals. The LCD apparatus 100 of the present invention further
comprises a light adjustment plate 130 disposed between the TFT-LCD
module 110 and the phase retarder 120 and configured to reduce an optical
path difference of a light emitted from the phase retarder 120. When
using the LCD apparatus 100 of the present invention, the light
adjustment plate 130 can reduce the optical path difference of the light
emitted from the phase retarder 120, thus reducing a light output area of
the left or right eye pixels on the phase retarder 120. Therefore, it can
be mitigated that the pixel signals for left eye pass through the
λ/2 phase retarder to form horizontal left eye signals (should be
vertical left eye signals), and similarly, it can be also mitigated that
the pixel signals for right eye pass through the zero-wave phase plate to
form vertical right eye signals (should be horizontal right eye signals).
In this manner, crosstalk can be prevented.

[0027] In FIG. 4 which is the structural diagram showing the LCD apparatus
according to the preferred embodiment of the present invention, a
refractive index of the light adjustment plate 130 is larger than a
refractive index of a liquid crystal layer 113 of the TFT-LCD module 110.
When the refractive index of the light adjustment plate 130 is larger
than the refractive index of the liquid crystal layer 113 of the TFT-LCD
module 110, a refractive angle of light rays emitted from the liquid
crystal layer 113 to the light adjustment plate 130 is less than an
incident angle of the light rays emitted from the liquid crystal layer
113 to the light adjustment plate 130, thereby reducing the optical path
difference of the light emitted from the phase retarder 120. Thus, the
light output range can be reduced for preventing crosstalk.

[0028] There are some manners for altering parameters of the light
adjustment plate 130 of the LCD apparatus 100 of the present invention,
so as to reduce the optical path difference of the light emitted from the
phase retarder 120.

[0029] In a first manner, a thickness of the light adjustment plate 130 is
increased, so as to reduce the optical path difference of the light
emitted from the phase retarder 120. When a material of the light
adjustment plate 130 is determined, the refractive index of the light
adjustment plate 130 is limited. The refractive index of the light
adjustment plate 130 may be larger than the refractive index of the
liquid crystal layer 113 of the TFT-LCD module 110, and the thickness of
the light adjustment plate 130 is increased, thus reducing the optical
path difference of the light emitted from the phase retarder 120. The
thickness of the light adjustment plate 130 is increased, i.e. the
distance of light rays in air and between the light adjustment plate 130
and the phase retarder 120. Accordingly, in one pixel, the light output
range on the phase retarder 120 can be reduced for preventing crosstalk.
In this manner, any material of the light adjustment plate 130 is
allowed. However, when the refractive index of the light adjustment plate
130 is less, the light adjustment plate 130 is required to be thicker for
preventing crosstalk, thereby increasing a weight of the LCD apparatus
100.

[0030] In a second manner, the refractive index of the light adjustment
plate 130 is increased, so as to reduce the optical path difference of
the light emitted from the phase retarder 120. When altering the material
of the light adjustment plate 130, the refractive index of the light
adjustment plate 130 can be increased for reducing the optical path
difference of the light emitted from the phase retarder 120. Accordingly,
in one pixel, the light output range on the phase retarder 120 can be
reduced for preventing crosstalk. In this manner, by altering the
material of the light adjustment plate 130, the structure of the LCD
apparatus 100 can be invariable for improving crosstalk.

[0031] In a third manner, the thickness and the refractive index of the
light adjustment plate 130 can be varied at the same time, so as to
reduce the optical path difference of the light emitted from the phase
retarder 120. When altering the thickness and the refractive index of the
light adjustment plate 130, the integrated parameters are considered. For
example, when a material of high refractive index is used, the thickness
of the light adjustment plate 130 can be reduced for improving crosstalk
and enhancing display quality (for example, too much refraction of the
light adjustment plate 130 may deform the displayed frame, hence
affecting display quality). When a material of lower refractive index is
used, the thickness of the light adjustment plate 130 can be increased
for improving crosstalk.

[0032] In FIG. 4 which is the structural diagram showing the LCD apparatus
according to the preferred embodiment of the present invention, the light
adjustment plate 130 further comprises a black matrix 131 for improving
crosstalk. The black matrix 131 is disposed on the light adjustment plate
130 of the LC panel. For separating the RGB pixels, the black matrix 131
is in the shape of a grid or stripes. The light adjustment plate 130 can
prevent the TFT-LCD module 110 from an interference of an external light
source. The material of the black matrix 131 may be Cr, low reflective Cr
or resin material. An area of the black matrix 131 of the LCD apparatus
100 of the present invention can be reduced by using the light adjustment
plate 130, so as to improve crosstalk and ensure the aperture ratio of
the LC panel. The cooperation of the black matrix 131 and the light
adjustment plate 130 can achieve the best effect of preventing crosstalk
and ensuring the aperture ratio of the LC panel.

[0033] In the preferred embodiment, the phase retarder 120 may comprise an
assembly of the zero-wave phase plate and the λ/2 phase retarder,
or an assembly of quarter-wave (λ/4) phase retarders having
slow-axis angles of 45 degrees and 135 degrees. When using the assembly
of the zero-wave phase plate and the λ/2 phase retarder, glasses
which have a horizontal polarization absorption glass at one side thereof
and a vertical polarization absorption glass at another side thereof are
required for 3D display effect. When using the assembly of the λ/4
phase retarders having slow-axis angles of 45 degrees and 135 degrees,
glasses which have a left-handed circular polarization absorption glass
at one side thereof and a right-handed circular polarization absorption
glass at another side thereof are required for 3D display effect. The
user can choose a suitable assembly for forming polarized signals for
left or right eye according to real requirements.

[0034] A working process of the LCD apparatus of the present invention is
described cooperated with a structural diagram according to the preferred
embodiment shown in FIG. 4.

[0035] The LCD apparatus 100 comprises the TFT-LCD module 110, the
corresponding phase retarder 120 and the light adjustment plate 130. The
TFT-LCD module 110 comprises the pixels 111 for left eye signals, the
pixels 112 for right eye signals and the liquid crystal layer 113. The
black matrix 131 is disposed on the light adjustment plate 130. Referring
to FIG. 4, the light rays emitted from lamps pass through the pixels 111
for left eye signals, the liquid crystal layer 113, the black matrix 131,
the light adjustment plate 130 and the phase retarder 120 in sequence.
The refractive index n2 of the light adjustment plate 130 is larger than
the refractive index n1 of the liquid crystal layer 113 of the TFT-LCD
module 110, and the incident angle of the light rays entering the light
adjustment plate 130 is θ1, and the refractive angle of light rays
passing through an interface of the light adjustment plate 130 is
θ2. According to Snell's Law: n1*sin(θ1)=n2*sin(θ2), a
reduction [D*tan(θ1)-D*tan(θ2)] of the optical path
difference (OPD) is obtained, wherein D is the thickness of the light
adjustment plate 130. When n2 is getting larger, θ2 is reduced, and
the OPD is also reduced, thereby preventing the light rays from entering
a wrong range for improving crosstalk. As shown in FIG. 4, the reduction
of the OPD can be controlled by altering the thickness D or refractive
index of the light adjustment plate 130. For example, the refractive
index n1 of the liquid crystal layer 113 is 1.5, and the thickness D of
the light adjustment plate 130 is 700 um, and the incident angle θ1
is 30 degrees, and the refractive index n2 of the light adjustment plate
130 is 1.7. Thus, the reduction of the OPD is 404 um-344 um=60 um.
Normally, the refractive index of the liquid crystal layer 113 is less
than 1.5, and the refractive index of the light adjustment plate 130 is
in the range of 1.5 to 1.7.

[0036] By altering the thickness and the refractive index (the refractive
index between the liquid crystal layer 113 and the phase retarder 120) of
the light adjustment plate 130, the LCD apparatus 100 of the present
invention can reduce the incident angle and OPD of the light rays, so as
to prevent the light rays from entering a wrong range of the phase
retarder 120 for improving crosstalk. In that manner, the area of the
black matrix can be reduced for prevent crosstalk in 3D displaying and
enhancing the aperture of the LC panel.

[0037] In another embodiment of the present invention, the light
adjustment plate 130 may be disposed in the TFT-LCD module 110 for
reducing the optical path difference of the light emitted from the phase
retarder 120. At this time, the light adjustment plate 130 may be one of
two substrates of the TFT-LCD module 110. For example, the light
adjustment plate 130 may be a glass substrate having color filters (CF).
Therefore, similar to the above-mentioned description, the parameters,
such as the thickness or the refractive index, of the light adjustment
plate 130 of the TFT-LCD module 110 can be varied for reducing the
optical path difference of the light emitted from the phase retarder 120.

[0038] The present invention has been described with a preferred
embodiment thereof and it is understood that many changes and
modifications to the described embodiment can be carried out without
departing from the scope and the spirit of the invention that is intended
to be limited only by the appended claims.